grayback vs Calidris canutus

grayback and Calidris canutus both are nouns.

Word	Noun	Adjective	Verb	Adverb
grayback	Yes	No	No	No
Calidris canutus	Yes	No	No	No

As nouns, grayback and Calidris canutus are synonyms defined as:

grayback and Calidris canutus: a sandpiper that breeds in the Arctic and winters in the Southern Hemisphere

Other synonyms of grayback include greyback, knot.

grayback (noun)	Calidris canutus (noun)
a dowitcher with a grey back	a sandpiper that breeds in the Arctic and winters in the Southern Hemisphere
a sandpiper that breeds in the Arctic and winters in the Southern Hemisphere